The present invention relates to the locating of signal sources, particularly sound signal sources, under utilization of several spacially separated sensors or tranducers producing output signals which are linked under utilization of the principle of a cross-power density for purposes of producing information being indicative of the direction of the located signal sources.
For locating signal sources it is customary to acquire signals of interest, particularly signals within a certain range, by means of appropriately configured and designed sensors and transducers, and to evaluate the signals as received in accordance with a particular procedure. For example, sound sensors, such as microphones, monitor a certain area, for example, in the military field, in order to locate as soon as possible sound-producing target sources. Adequate function requires of course that undesired noise signals, i.e., signals from sources other than those of the type one wishes to locate, do not interfere in the locating procedure. However, this is a presumption which cannot always be made. Therefore, in the general case it will be necessary to suppress noise and noise signals in order to separate them from signals transmitted from sources which are to be located. This is particularly important if, for example, the locating device itself is mounted on a noise-producing vehicle. In such a case, it is possible to locate sound sources only if in fact the sound produced by the vehicle on which the equipment is mounted, can be suppressed. Herein of course it is of particular significance that this noise-producing source is located much closer to the sensor than any of the target sources; the noise may be much stronger than the acoustic signals to be detected.